Dainiaus webaz – elektronika ir ne tik !

Šito reikalo istorija tęsiasi jau kokia 15 metų, tai pradėsiu iš toli. Kažkada, dar universiteto laikais, prisireikė programatoriaus, tuomet ant bangos buvo Willem’as, tuomet jį pasidaryti buvo galima sąlyginai nesunkiai, o svarbiausia gerokai pigiau nei pirkti gamyklinį programatorių. Dirbo per LPT (DB25) prievadą, reikėjo konfigūruoti trumpikliais ir buvo lėtas, bet skaitė kažkuriuos EEPROMus, kurių kiti pigūs programatoriai „neįkąsdavo”, nors su tais EEPROMais dirbo dar lėčiau (o gal ten buvo EPROMai). O dabar irgi pilna jo klonų, AliExpress’e ir šiaip pas entuziastus. O aš kažkaip nenorėjau tokio, reikėjo gero, universalaus, dirbančio per USB prievadą ir tuomet pirkau AliExpress’e TOP2048 programatorių. Nors jo programa (TopWin 6) buvo stipriai Chinglish, bet jis buvo pigus (anuomet mokėjau gal 78 $) ir su labai dideliu palaikomų mikroschemų sąrašu. Ir puikiausiai juo naudojomės tikrai ilgą laiką, kol pagaliau įsirėmėme į Windows 10 ir faktą, kad TopWin programa nu niekaip nesusibendravo su Windows 10 ir programatoriaus draiveriu. Po to kurį laiką dar bandė tas programatorius dirbti Windows XP aplinkoje, bet sukosi virtualkėje, bet dabar, atsinaujinus laboratorijos kompiuterį, sugalvojau, kad reikia atsinaujinti ir programatorių. Ufff, va tokia va tatai istorija, kodėl čia viskas atsitiko. Taigi, išstudijavęs rinkoje esančius programatorius, palyginęs jų galimybes, savo poreikius ir finansinius pajėgumus pasirinkau Batronix BX48 Batego II universalų programatorių. Jis atitiko visus pagrindinius pasirinkimo kriterijus:

• Gaminamas Europoje
• Geras palaikymas, pageidautina Europoje
• USB jungtis
• Dirbantis su Windows 10 ir Windows 11
• Didelis palaikomų mikroschemų sąrašas
• Patogi programa

Taigi, Batronix – Vokiečių įmonė, reikia tikėtis vis dar išlaikiusi ta vokišką kokybę. Palaikymas – kurį laiką bendravau, patiko, ypač tai, kad pasakė – „jeigu kokios mikroschemos nėra sąraše, pridėsime pagal pageidavimą ir greičiausiai nemokamai”. USB juntis yra, ką tik instaliavau ir išbandžiau Windows 11 operacinėje – veikia, programa tikrai funkcionali, tai kol kas visko net neišbandžiau, bet kiek bandžiau patiko. Ne viskas joje ten gal patogu, kai kada atrodo, kad net per daug funkcijų, bet tas žymiai mažiau trukdo, nei funkcijų trūkumas. O kad jau turim gamintoją, tai štai ir jų gaminamų programatorių palyginimas:

Kadangi programatorių perku tikrai ne vieniems metams ir negali žinoti, kokias mikroschemas gali tekti programuoti ateityje – pasirinkau patį pačiausią, BX48 Batego II už 579,59 € (tiesa gavau nedidelę nuolaidėlę ir nemokamą siuntimą).

Forma patiko, juodas, mažiukas, su trim LEDukais ir didele ZIF jungtimi mikroschemoms. Dabar beliko tik užsipirkti reikiamų adapterių, kol kas tik PLCC-44. Palaikomų mikroschemų sąrašas yra čia. Svarbiausia, kad palaiko ir visokius senus ir jau ekskliuzyvinius čipus :).

Posted in: Programatoriai by Dainius /
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Prieš kurį laiką įsigijau ir ST Link V2 programatorių, originalas, gražioje dėžutėje. Aprašymas iš ST puslapio:

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The ST-LINK/V2 is an in-circuit debugger and programmer for the STM8 and STM32 microcontrollers. The single-wire interface module (SWIM) and JTAG/serial wire debugging (SWD) interfaces are used to communicate with any STM8 or STM32 microcontroller located on an application board. In addition to providing the same functionalities as the ST-LINK/V2, the ST-LINK/V2-ISOL features digital isolation between the PC and the target application board. It also withstands voltages of up to 1000 V_rms.

STM8 applications use the USB full-speed interface to communicate with the ST Visual Develop (STVD-STM8) or ST Visual Programmer (STVP-STM8) software, or with integrated development environments from third-parties.

STM32 applications use the USB full-speed interface to communicate with the STM32CubeIDE software tool or with integrated development environments from third-parties.

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Pas mane tas paprastesnis, be izoliavimo. Skirtas STM8 ir STM32 valdikliams programuoti/debuginti.

Posted in: Programatoriai by Dainius /
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Kad pats nepamirščiau kaip… Įsidiegiam MathML block įskiepį, o tada sintaksė yra čia.

Posted in: Naudinga informacija by Dainius /
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Prisireikė man čia vienam projektukui stabilizuoti maitinimą, kad išsikraunant baterijai (9 V) įtampa būtų stabili (6-7 V). Vienas paprasčiausių būtų tą padaryti būtų DC-DC keitiklio naudojimas ir jau galvojau dėti jau pamėgtus Mornsun moduliukus, šiuo atveju K7812JT-500R3-LB (6,5 V 500 mA):

Kainuoja centus, efektyvus, stabilus ir geras. Bet kaip visada, lengviausi sprendimai ne man , todėl prisiminiau tokį senovišką žodį stabilitronas. Dabar tas daiktas vadinamas Zenerio diodu. Nebus jis toks jau stabilus temperatūriškai, bet šiuo atveju tiks, nes reikia pasikartoti skaičiavimo teoriją. Tipinė schema tokia:

Tranzistorius gali būti priešingo poliarumo, tada schema truputį kitokia. Bet schemoje visi tranzistoriai NPN tai tokį naudosiu ir stabilizavimui.

Teorija tokia – šitoks įtampos reguliatorius, sudarytas iš bipoliarinio tranzistoriaus, pajungto pagal emiterinio kartotuvo schemą, kurį valdo įtampos daliklis iš rezistoriaus ir stabilitrono. Daliklio išėjimas valdo tranzistoriaus bazę, taip valdydamas įtampą išėjime. Principe užtektų vien tik stabilitrono, bet su tranzistoriumi gaunama žymiai didesnė srovė išėjime. Svarbūs tranzistoriaus parametrai – maksimali srovė ir h_FE. Susižymime sroves ir jų kryptis:

Schemoje naudojami MMBT3904 tranzisotriai, 40 V, 200 mA, h_FE nuo 30 iki 300, priklausomai nuo kolektoriaus srovės.

Pagal kolektoriaus srovę manyčiau, kad h_FE bus apie 200, todėl tokį skaičių ir naudosiu. Taigi, turime, kad h_FE = 200, maksimali srovė 100 mA (realiai ten kokia 10 mA tereiks), skaičiuojame:

Iš čia:

Toliau prisiminkime mūsų geriausio draugo Kirchhofo taisykles. Pagal jas, srovė per R1 bus lygi srovės per D1 ir bazės srovės sumai.

Žiūrim pasirinkto stabilitrono BZT52C6V8-7-F dokumentaciją:

I_ZT = 5 mA, t. y. reikia bent 5 mA (0,005 A), kad diodas būtų grūtinėje voltamperinės charakteristikos zonoje.

Naudojame 6,8 V stabilitroną, o maitinimas bus nuo 9 V baterijos (Krona arba 6LR61), tai ant rezistoriaus R1 turime nusodinti 9 – 6,8 = 2,2 V. Kai jau turime srovė per rezistorių ir įtampą, dėdės Omo dėsnio pagalba skaičiuojame rezistoriaus varžą:

Jeigu baterija jau pasėdusi ir įtampa pakris, tarkim, iki 8 V, tuomet 8 – 6,8 = 1,2 V ir:

Taigi, norint, kad schema veiktų prie 8 V, reikėtų naudoti 220 Ω rezistorių. Prie 9 V tuomet stabilitrono srovė bus 10 mA.

Ir dabar galima atsinaujinti schemą:

Kondensatorius nelabai reikalingas, bet 1 uF mažiulis irgi nepamaišys.

Posted in: Elektronika by Dainius /
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Prieš kokius metus turbūt pradėjau rinktis detales ir panašu, kad jau netrukus bus galima instaliuoti Windows 10 (taip, W11 manęs kažkaip nesužavėjo, tai kol galima dar patempsiu su W10). Šiandien gaunu paskutinį komponentą – M2 diską. Taigi, supeiksite ar pagirsite sistemą:

Dėžė kokia nebeprisimenu, bet pagrindinė plokštė MSI Z590 PRO WIFI. Gamintojo puslapis, specifikacijos, suportinamas hardwaras.

Procesorius Intel i9-11900K. Indeksas „K” reiškia, kad procesorius be video posistemės, bet taip ir turėjo būti, nes bus atskira video korta. Aušintuvas HYPER 212 LED. Tokį patį naudojau ir prieš tai buvusiame laboratorijos kompiuteryje. RAM – Crucial CT16G4DFRA32A, keturi kauliukai:

Komponuotė be video kortos:

Maitinimo blokas Corsair RM850x.

Diskas duomenims – 8 TB WD8004FRYZ, SATA, CD/DVD diskasukis ASUS DRW-24D5MT.

Šiandien prie jų prisijungs 1 TB atmintukas SILICON POWER SSD XPOWER XS70 1TB M.2 PCIe Gen4 x4 NVMe 7300/6800 MB/s, SP01KGBP44XS7005.

Video korta Gigabyte GeForce GTX1660 Super:

Prie to dar bus 3½ FDD diskasukis, įvairių kortelių skaitytuvas ir gal dar kas nors.

Manyčiau, kokiems 10 metų užteks . Bet pasirodo nusipirkęs buvau Windows 11 PRO x64, tai instaliavau. Bandau perlaužti smegenis, kad dirbtų su šita OS.

Posted in: Kompiuterija by Dainius /
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Pirmą kartą remontui papuola Velleman WFS210 oscilografas, taigi bus įdomu susipažinti su daikčiuku.

Pirminis nusiskundimas – kadangi oscilografas duomenis perduoda į kompiuterį WiFi ryšiu, neveikia prisijungimas, nes kažkodėl sukurtas WiFi tinklo pavadinimas neatitinka standartinio. Sukuriamas WiFly-EZX-d8 tinklas, vietoje reikiamo WFS210(?).

Taigi, pirmas spėjimas – kažkas kažkada prišamanino ir galbūt bandė įprogramuoti kokį nors netinkamą arba modifikuotą programą, dėl to dabar oscilografas nuprotėjo, o WiFi pavadinimas toks nestandartinis. Reiškia reikia bandyti perrašyti originalią programą. Gėris tame, kad Velleman puslapyje ji duota. Taigi, programą parsitempiau, tik dabar kaip ją įrašyti ? Kaip ir logiška, kad jeigu oscilografas turi USB ir jam dedikuotą programą, tai joje turėtų būti ir kontrolerio programos atnaujinimo funkcija. Turėtų būti, bet nėra. Ir čia pasimato, kad tas oscilografas toks labai žaislinis, spėčiau kokio elektronikos bakalauro baigiamasis, kuri Velleman’as sėkmingai prichvatizavo. O tai reiškia, kad nei pats prietaisas nei jo programos nebus tokios geros, kaip normalių ir profesionalių gamintojų. Bet – jeigu tiek tereikia, tai kodėl gi ne.

Bet dabar atsiranda klausima, tai kaip tą oscilografo programą jam sukišti ? Įdėmiau pažiūrėjus radau stebuklingas raides ICSP (In-Circuit Serial Programming). Įprastai tokios raidės ir šalia esanti jungtis įgalima tiesiogiai prisijungti prie procesoriuko su programatoriumi.

Tai kaip ir OK, tik va – koks tas procesoriukas ? Nes jiems skirtingi programatoriai. Ardom truputį daugiau, o tai visai ne lengva, nes reikia pažiūrėti po ekranu. Bet finale – ten gyvena PIC33EP256MU806.

Šita mikroschema yra skaitmeninis signalų valdiklis (DSC – Digital Signal Controller), turintis savyje DSP (Digital Signal Processor). Taigi, viskas komplektas viename – skaitmeninio signalo apdorojimo dalis + mikroprocesorius ir dar šiokia tokia periferija kitoms funkcijoms. Reiškia turėtų tikri PicKIT 3 arba PicKIT 4 programatorius, kontaktų reikšmės vienodos, tai pajungimas neturėtų skirtis.

Bandom jungtis:

Berods pavyko:

Programuojam:

Patikrinam, ar teisingai įsirašė:

Nors ir nuskaitytas įrašas nesutampa su bandytu įrašyti failu, visgi prisijungimas veikia – ištrynus procesoriaus atmintį „Blank check” praeina, įrašius kažkokius duomenis nuskaito. Chm, ar gali būti, kad procesoriuko atmintis buvo tiek kartų rašyta ir skaityta, kad dabar jau „susidėvėjo” ir dėl to nebeįsirašo adresas 0x0, todėl vietoje reikiamų 0x00040200 nuskaitomas 0x00000000. Bet gal čia ne kritinis dalykas arba kažkas čia dar prišamaninta ir kitaip nebus. Esmė, kad WiFi pavadinimas nepasikeitė, tai matyt toks jis ir turi būti…

Šiandien sugalvojau truputį dar pagalvoti apie tą WiFi pavadinimą. Taigi, tas WiFLY GSX yra tiesiog WiFi ryšio modulis, kuris buvo stumdomas Sparkfun’o ir kitų elektronikos komponentų tiekėjų, bet dabar jau pasenęs ir išimtas iš pardavimo: WiFly GSX 802.11b/g Serial Module – Roving Networks – WRL-10004 – SparkFun Electronics. Modulio aprašymas yra čia. Taigi, dabar tokia teorija – jeigu modulis sveikas, bet nesukonfigūruotas, jis užsikuria, paleidžia WiFi tinklą su kažkokiu standartiniu (default) pavadinimu ir nustatymais. O tai reiškia, kad oscilografo procesoriukas jo nesukonfigūruoja taip, kaip numatyta procesoriuko programoje, nesukuria tinklo reikiamu pavadinimu. O kad jau nedaro šito darbo, tai man dabar kyla klausimas – o tai jis iš viso kažką daro ? Nes signalų pamatyti nepavyko ir per USB jungtį. Tai gali būti, kad kažkokia procesoriuko dalis pasimiro, nes nors ir kreivai, bet veikia programavimo funkcija, gal dar kokia nesusijus periferija, bet nei matavimų nei WiFi modulio konfigūracijos jis nebedaro. Spėčiau, kad mirusi skaitmeninio signalo apdorojimo dalis (nes nėra jokių požymių, kad bandytų parodyti matuojamą signalą) ir kartu nusinešė vieną UART komunikacinį kanalą (nes neveikia WiFi modulio konfigūravimas). Tai bandom pakeisti procesoriuką ?

Posted in: Elektronika by Dainius /
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I noticed that retro hardware posts are also read by foreign readers, so to make it easier, this time writing in English. Ok, what do we have today :

It seems to be some dedicated PC with markings:

APLUS-LECT-CM16-A
CEL1007-098452

LECTRA
Ref fab: APLUS-LECT-CM16-A
Code article: PCAPLUS/CM16
Indice technique: A

Wrote those, so Internet search engines would find them as text and index the information for someone who might search the same information. The form factor of the PC is not standard, box most probably is custom made (can still see the lines left by bending press).

Here we see the internal structure – Mini-ITX motherboard with PCI port raiser and RAM, fancy power supply, HDD and fan. The interesting thing about this PC is that it has many RS-232 ports – four ports are routed the back panel and I think there are one or two connectors on the motherboard for more RS-232 ports. This makes this PC perfect for controlling multiple RS-232 devices, for example, 3D printers, plotters, CNC and so on. Otherwise, it’s not really a retro HW, but because of multiple RS-232 ports it deserves to be here.

This motherboard combines old technology and new technology, for example it has the Parallel ATA (both normal size and small 44 pin connectors) and SATA connectors for HDD, could have also TPM module and LVDS connector and controller (missing on this motherboard – controller should be under the CMOS battery and LVDS connector on the left side).

The two Gigabit controllers Realtek RTL8110SC, drivers are here. LPC port controller (including all other of the IC functions) Winbond W83697HG, which is the same as W83697HF, but is pb-free.

The bottom part of the motherboard. We can see that there is a solder place for CF card connector.

The motherboard is KINO-6612, quick installation guide is here.

As quick installation manual has a lot of information on jumper settings and other things, I am not going into details here, but you might want to read it. Also, the full manual but for LVDS version of this motherboard is here. Both manuals will be handy, when we start upgrading this PC to the max.

The main processor:

Intel Celeron M 380 processor, SL8MN, clocked at 1,6 GHz in mPGA479M socket.

North bridge SIS661CX, notice, how much thermal paste it had . And SIS964 IC as South bridge. And the diagram, indicating who is who and what does what :

Some markings on the motherboard for easy identification:

00DE026-01-120-RS
KINO-6612-R12 REV: 1.2
94552202019 I410 19
ICP-KINO-6612-R12

First thing – PC cleaned, put a decent amount of thermal paste on the chipset radiator (yes, using the same Thermal Grizzly). And we will continue with installing new processor, max RAM and SATA SSD. Most probably, this PC will run Windows XP, or maybe Windows 98 SE. Not yet decided.

After reading the manual, I found, that best supported processor is Intel® Pentium® M Processor 780, 2M Cache, 2.26 GHz, 533 MHz FSB, SL7VB. Comparison with current processor:

Intel® Product Specification Comparison
	Intel® Celeron® M Processor 380	Intel® Pentium® M Processor 780
Essentials
Product Collection	Legacy Intel® Celeron® Processor	Legacy Intel® Pentium® Processor
Vertical Segment	Mobile	Mobile
Processor Number	380	780
Status	Discontinued	Discontinued
Lithography	90 nm	90 nm
Performance Specifications
Total Cores	1	1
Processor Base Frequency	1.60 GHz	2.26 GHz
Cache	1 MB L2 Cache	2 MB L2 Cache
Bus Speed	400 MHz	533 MHz
FSB Parity	No	No
TDP	21 W	27 W
Scenario Design Power (SDP)	0 W
VID Voltage Range	1.004V-1.292V	1.260V-1.404V
Supplemental Information
Embedded Options Available	No	No
Memory Specifications
Physical Address Extensions	32-bit	32-bit
ECC Memory Supported	No	No
Package Specifications
Sockets Supported	PPGA478 H-PBGA479	PPGA478 H-PBGA479
TJUNCTION	100°C	100°C
Package Size	35mm x 35mm	35mm x 35mm
Processing Die Size	87 mm2	87 mm2
# of Processing Die Transistors	144 million	144 million
Advanced Technologies
Intel® Turbo Boost Technology	No	No
Intel® Hyper-Threading Technology	No	No
Intel® Virtualization Technology (VT-x)	No	No
Intel® 64	No	No
Instruction Set	32-bit	32-bit
Idle States	No	No
Enhanced Intel SpeedStep® Technology	No	Yes
Intel® Demand Based Switching	No	No
Security & Reliability
Intel® Trusted Execution Technology	No	No
Execute Disable Bit	Yes	Yes

The processors, old and new:

Digital beauty! Also, 2x1GB RAM already installed.

First run, to test if CPU and RAM are working successful. BIOS shows some information, but the BIOS battery is dead, will have to be replaced. Also – when turned on the PC, thought that Boeing 747 is taking off nearby – the sound of the fans is very loud. CPU fan has ball bearings, so will try to replace those if possible, if not – the fan will have to be replaced, together with case and PSU fans.

Ordered some new bearings, dimensions 2 (hole) x 5 (outside) x 2,5 (height) mm, but while waiting for bearings lets search for suitable replacement of the fans. First – chassis fan, original KDE1206PTV1.MS.AF.GN is obsolete and not supplied anymore, so suitable replacement could be MF60251V1-1000U-G99 by the same manufacturer Sunon. Differencies:

• Current rating 0,14 A → 0,075 A
• Power 1,7 W → 0,9 W (sometimes fan control circuit doesn’t like less wattage)
• Fan efficiency 39,93 m³/h → 39,72 m³/h
• Noise level 33,5 dBA → 27 dBA

All the other thins are the same or not important if different (like cable length 290 mm vs 300 mm). In fact the fan will be much better – less power consumption and noise at the same air volume and ventilation level. Unless the control circuit will indicate fan malfunction, if current will be different than expected 0,14A. In that case – I’ll just replace the bearings and use original fan.

Reminder of the original fan schematics and charts:

Next – CPU fan. Original R125010BH (50 x 50 x 10 mm). Choosing the replacement fan we have to consider, that we just installed the most powerful processor for this motherboard, so maybe we would like to have a bit more powerful fan. And I chose . Differences:

• Depth 10 mm → 15 mm (we have plenty of space, so 5 mm higher fan – no problem)
• Airflow 10 CFM (17 m³/h) → 12,9 CFM (22 m³/h) (good, more air – better cooling)
• 30,1 dBA → 23 dBA
• 3 W → 1,8 W

So again, more air volume, less power consumption and noise. But the fan is higher, so we might need to adjust its mounting holes or screws (they will be too short).

PSU fan by ADDA CORP. model AD0412HB-D50, specification:

Substitute – Delta Electronics AFB0412HHB. Comparison:

• Current 0,12 A → 0,13 A
• Power 1,44 W → 1,56 W
• Speed 8000 RPM → 8300 RPM
• Air flow 9,2 CFM → 11,48 CFM
• Pressure 0,287″ → 0,359″
• Noise 39,3 dBA → 32 dBA

So, at a little bit more power consumption we still win at air flow and noise , nice.

To be continued.

Posted in: Retro PC HW by Dainius /
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Another PC for my retro PC collection, the first and only laptop sized computer. Picture from Internet:

The specs are not impressive today, but back in the days, when it was shiny and new – they were pretty decent, running Pentium Celeron at 800 MHz. Have to say, that it’s not the oldest possible laptop, but I took it because it matches required the time frame of laptops – it’s able to run Doom . Checked the PC and it appeared to be working fine, just need to have some minor work done. First of all purchased some plastics on eBay as the housing was old and cracked in some places (especially around display hinges). While replacing the plastics cleaned it thoroughly from the dust of ages, put some new thermal grease on CPU and assembled it all back. For the next tasks I thought it would be nice to have Floppy disk drive and DVD ROM drive. Original floppy drive was missing, but luckily with the plastics from eBay I got also some more parts – keyboard, floppy drive and hinges. Well, keyboard is damaged and missing some keys, floppy drive is not working, but hinges are good – all this was said by the seller, so it’s OK. Even the faulty floppy is useful – it provided information what exactly part number I need and in couple of days I purchased the floppy on the same eBay:

To be honest there were more sellers with same drives, but I took the most expensive, because in the picture the drive seemed to be like new and the seller wrote in the add that drive is 100% working. Some time passed and the drive reached me . What a joy, at last I will be able to assemble the PC and make some tests with it. The CD to DVD drive replacement could be done later, because it does not require disassembly of the housing (for that I so much like retro hardware). Assembled everything, by the way, by super thorough and cautious with hinges covers, their fixation parts are super fragile, I broke the original fixators, but replaced covers with second set I got with the plastics. But if you don’t disassemble the PC if you don’t really really need that. Ok, the bolts are in places, keyboard in place, plastics mounted – lets turn it on for floppy test, first some data transfer from the PC to laptop:

What a disappointment, drive just makes this clicking sound and nothing more… After some time Windows asks for a Floppy… So many hopes just flew out of chimney and those were not cheap, 33,76 € to be exact. The faulty floppy drive I got, for future reference, if I would need to look for another drive:

As for now – wrote the seller, maybe it’s not the drive from the add (that drive had blue heads cover, seen in the original picture). Now let’s wait for decision.

The seller said that she (yes, it appeared to be a woman) has an electronics laboratory and agreed to take back the FDD for checking. After some chatting, we agreed that I will send 3 drives to be checked and confirmed they are OK or repaired if not. I’ve send it on 2022.10.20, later will put a scan of the Post office receipt. Now its 2023.02.23, but I sill have no good news about those FDDs, in some time I will add all the chatter that we made in WhatsApp, now, while hope is still alive, don’t want to disclose too much of personal information . But I also have a good news – today purchased another FDD on eBay, so lets wait till I receive it, maybe finally that laptop will be assembled. To be honest, I am a bit nervous seeing it on my table so long…

2023.06.19

Long time passed, I’d like to finish the article and move on to the next projects.

Ok, so first about the seller of the faulty FDD. It was quite clear long ago, but now I am sure – seller stole my disk drives, no answer on the eBay chat, phone or WhatsApp, so it is safe to make this conclusion. Last message on eBay chat:

And the complete chat I uploaded as separate thread here.

WhatsApp conversation:

I hope you feel the naive sarcasm in my messages . So, guys, if you would happen to visit Italy, you might stop by and politely ask Daniela to return me my FDD drives. The address is: Daniela Paschina locality Guistrigona 12E Casteluovo Berardenga 53019 (SI).

So I checked the eBay and found another FDD for this laptop, purchased it and short after I received the parcel. Unfortunately, the FDD was a bit damaged, metal frame was bent, some dents visible on the connector side of the FDD, but other than that it looked OK. So I wrote to the seller:

Naturally, photos were added:

Once again, I want to take the opportunity to thank Claudio for the most proper reaction, sincerity and understanding. I disassembled the drive, used some of the metal frame parts from the FDDs that I had, other metal parts straightened – and after that installed the FDD to laptop. IT WORKS !!! Claudio – you are the best, thank you so much ! After so much effort at last the laptop is assembled and is working. FDD reads and writes the floppies perfectly. So I can confirm, that:

is selling good and working parts on eBay, with perfect attitude towards the customer. Good luck !

Posted in: Retro PC HW by Dainius /
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The names of those power supplies are different, but inside they are all the same, with veeery slight differences. The brand names are Wanptek, Hanmatek, Naweisz, Sky TopPower, Circuitspecialists, Eventek and bunch of other brands and even without any brand, they all look pretty much the same and are priced at about 70-80 €.

The internals of the power supply are the same and looks like this:

Pictures takes from the power supply I got for repair, exact model is KPS1505D, one of other models, sold by this „manufacturer”:

The power supply had burned main fuse (3A), so it was not long to find out that power transistors and diodes gave their souls to the god of electronics in form of smoke. And we all know – all electronics is made of smoke, when it goes out, electronics stops working. Well, before repairing, lets study this board for a while. By the way – as this power supply is so typical, I am not explaining about its functionality, controls and basic things like that.

The main PCB is marked POWER-ZB-02 2022.01.10:

The white connector on the bottom right is for 230AC input and all this bottom part along the PCB is for input filtering, rectifying and stabilizing. So right to left – yellow input capacitor, common mode (CM) filter, which, with its ‘current compensated’ windings, provides high impedance to CM noise without saturation from line current, two small blue caps and one more yellow capacitor. Then a small diode bridge, yes, yes, the fuuuuuuull bridge rectifier (DB107S). This rectifier, together with the nearby electrolytic capacitor, that strange IC with 7 pins (TNY280GN) and JKL-10-12 transformer (skipping some minor SMDs) forms low power supply for logic and control ICs, LED indicators, etc.

The bigger rectifier (KBL610) and two big electrolytes are for the power section of the device.

And on the left side of the PCB a place for missing connector, it wasn’t there, but on the other boards the main power selection switch (115VAC/230VAC) is connected. This version of device has no connector on the PCB and switch on the back panel, so, if you want to use it with low voltage power system just connect those two pins on PCB or put a switch – when pins shorted use 115VAC, when open use 230VAC. The rest of the board is, basically used to hold the main controller (TL494C). The TL494 or its clones or variants are used in all sorts and kings of PWM power supplies and, probably, in 95% of their population.

As this IC is so popular, there are plenty of schematics with it on the Internet, which would help you to make the repairs. I was surprised, but this version of board has all electrolytic capacitors marked as low ESR, which is good (hoping, that its not just marking ). Even those big input filtering caps (470 µF 250V) are low ESR, which is not really needed for their job.

One of three output caps is also Changxin 2200 µF 35V Low ESR, other two Sanyo 1000 µF 50V, together with a big and small choke, they form the output filter (on the top of PCB picture). And thick copper wires on the negative trace are shunts for current measuring.

In the middle part of the PCB the main component is TL494, couple of op-amps, one of them turns on the fan when aluminum board with transistors and diodes get hot. The temperature is sensed by 1N4148 diode, drowned into thermal paste. The last things are power transistors and diodes:

The big thing is a dual Schottky diode with common cathode – MBR30200PT. But the two transistors are blank, not marked , guess what are they. Ok ok, I tell you, its 2SK3569.

And yes, it’s not recommended for new designs, most probably you wouldn’t find them for purchase eather. Unless fake AliExpress clones. Luckily, we have me and I already selected proper substitute – AOTF15S60L. Why particularly this one ? Because at the date and time of repair it suits all requirements:

• Analog or better than 2SK3569
• Cheap
• Available for purchase

This transistor a slightly better that original, is almost cheapest (~2,5€/piece) from the selection and is available for order – perfect :).

Parts received and soldered in, surprisingly nothing exploded, and power supply shows the set voltage. But the test under load was not successful – connected 0,62 Ω resistor and raised voltage to raise the current. At some point heard a clap and everything turned off. The current was not high, I think it was about 6-7 A, but can’t say for sure – I did not expected it to explode, so did not looked at the display all the time and also display refresh rate is not instant. Nevertheless, fuse blown, most probably transistors and diodes also. Let’s disassemble it again and see what happened. But it worked with some small current, liek couple of amps, so it might be, that TL494 is counterfeit and cannot work normally under bigger loads, while the idea of this power supply is to be fearless when speaking about currents up to 10 A or short circuit. Luckily, I still have some transistors and diodes left .

To be continued after parts received and soldered in.

Posted in: Elektronika by Dainius /
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Posted in: Naudinga informacija by Dainius /
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