Pure Electronics Repair 2: Part 2 Learn Methodical Fault Finding Techniques To Fix Almost Anything

LER #306 Here we have the Arcade game PCB back again - it is still not working, This time I have another faulty one and a good working one of the same type so I should have a better chance to fix it Yeah?

I work in collaboration with:
The Electronics Channel (with Carlos and Detlef)

Gran Canaria Uncovered

For All Your PCB needs: free $5 discount coupon

Equipment used in my videos. These are affiliate links, you pay the normal price and I make a small commission.

TEST METERS
ANENG AN8009 MULITIMETER
KAIWEETS HT118E MULTIMETER
VC480C+ MILLIOHM METER
MESR-100 ESR METER
XC6013L CAPACITOR METER

TM-902C TEMPERATURE METER
LCR-T4 COMPONENT ANALYZER
FNB58 USB ANALYZER
PCI POST ANALYZER
TL460S PLUS PCI_E ANALYZER
TOOLTOP ET120MC2 SCOPE
FNIRSI 1014D SCOPE
NPS3010W 30V 10A PSU
T12 STATION WITH M8 9501 HANDLE
M8 9501 HANDLE
YIHUA 982 Soldering Station C210/C245
FNIRSI HS-02 PORTABLE SOLDERING C210/C245
QUICK 861DW
PROS'KIT SS-331H

INFIRAY P2 PRO IR CAMERA + MACRO LENS
TOOLTOP ET13S THERMAL CAMERA METER
ET13S MACRO LENS
OPTICAL MICROSCOPE
TOMLOV TM4K AF FLEX
TL866 II+ PROGRAMMER
CH341 PROGRAMMER
NC-559-ASM FLUX

DESOLDER BRAID (I use size 8045)
HX-T100 SOLDER (0.6MM)
ESD-11 TWEEZERS

If you would like to support this channel
You can send donations
You can subscribe to Patreon
You can click Join to become a channel member

Thank you
Richard

[alexguvera]

I'm a business advisor and binge watch your videos.
In-depth explanation and so much to learn.
Love from Pune, India. 🇮🇳

[Chipset]

New to your channel. Have dabbled with electronics and watched many u-tube channels.
I find your approach in explaining troubleshooting extremely informative.
Thanks. Looking forward to catching up on all your videos to date.

[Iceking]

Eagerly awaiting part 3!!! 😁

Who else was pointing at the screen and vigorously shouting "Ground Wire - Ground Wire - Ground Wire!" haha

Great stuff, thanks Richard; I'm a subscriber now, please keep it coming.

[wherami]

watching your video at 1.5 speed works pretty well . anything higher than that the speech becomes garbled. i have had a lot of people tell me of late they only watch videos on2x.

[budgiefish]

Looks like a pretty standard data bus/addressing setup there - the 573 will be used to select devices to read (chip enable) and will connect those devices bits to the data bus (you can see there's one per DIP switch), one for EPROM sockets... They're essentially parallel switches - in a normal (inactive) state the CPU will have nothing connected to the data bus (but will be connected to all the 573s in parallel), and the microcontroller will enable 573 chip 1 to connect all the data lines through to read the bits (1 or 0) from the 1st DIP switch, chip 2 to read bits from DIP switch 2, so on and the EPROM will be read similarly (but also with separate addressing lines) through another 573.

A live running diagnostic may be better, you can then firstly check for any stuck logic on the data bus (cpu side) as that will cause undeterminable problems :)

[hernancoronel]

Adrian from Adrian’s Digital Basement uses deoxit in sockets and other electronics with great success maybe you could try some of that stuff. You are an inspiration, thank you for your very educational videos Richard and keep up the great work!

[speedbeagle]

I recently tried to replace tracks on a CRT TV chassis that had been folded in half. I spent a few days in my spare time working on it, but in the end I got no love from it. Only reason I did it was because it was a 19" CRT and they're hard to find for arcades I build. It was a good exercise though I'm not sure I'd bother with it again. When something is this far gone I'm just not convinced it's worth the time.

[Dutch-linux]

it is a voice rec/play chip ISD2560P VOICE REC/PLAY youtube wont let me post the link to the chip but you can do a search for that

[jeremylaidman]

These boards must cost a small fortune to replace, to make it worthwhile you spending so much time on them, with no guarantee of success.

Great for us viewers though. I appreciate the time you're putting in.

[josherickson]

ISD1760PY-ND is the substituted part number. IC VOICE REC/PLAY 120SEC 28DIP. Hope this helps.

[davet]

Fascinating, better than most detective thrillers on Netflix!
I still need to know why the 5.6v regulator was getting so hot . 🤔

[KBUIF]

Rich, those chips look awfully like the common 28pin 27256 EPROM to me. I should say the EEPROM or write once PROM equivalents of the 27256 windowed version.
But looking it up they do appear to be the Voice Record / Playback chip ISD2560P. So based on that, maybe the one version speaks Spanish and the other speaks USA English.

[davesdigitaldomain]

after watching most of your videos it seems to me that a lot of the electronics in the Canary Islands seem to suffer with corrosion,

[BjornV]

Keep in mind that those red DIP switches are known to fail over time, even when they are not used often or even long periods of time in the same position.
This can gives strange results, because you don't expect that they can fail. I seems that the contacts become oxydized over time and the resistance goes way up.

[orionRS]

Boards this dirty should not even be measured, 10 second cleaning with contact cleaner and good brush can/will save hours of troubleshooting in wrong directions. Its good to have some habits and checklist what steps to do in which order to be good troubleshooter.
23:35 35:30 - DIP switches are on different positions while you were measuring. Could be unrelated, but could be related.
Some multimeters, in diode mode, bleep because they charge capacitors. Are you sure that this is not your case?
My method of checking multiple IC chips is following: First locate pin on board which is ground. Then use diode mode and red probe on that pin on IC, while IC is out of circuit. Then touch each pin of IC with black probe and write a chart. Then repeat for second IC, while both of them are out of circuit. Difference is easily spotted.
IF and only IF, board revisions are the same, this can be repeated for board slots for IC legs. Then investigate difference.
50:00 - Lemon acid can help to remove rust and battery leaks. Dont use strong chemicals they can ruin board even more.
Regarding the chip, I just googled "isd2560 circuit" and found circuit and pdf datasheet, I believe its what you need. Use website alldatasheet [dot) com and search part number ISD2560P.

[ralphj]

Interesting. Personally, I would not reconnect the original board (marked O). Re my previous comment, and unless there is a motor configuration I am not familiar with, you cannot connect 'both motors' to one of those stepper controller ICs. There is (probably) only one two phase stepper (which is odd for just a blower motor) which requires both ICs to drive it. it is no surprise the fuse went bang and I suspect some of the 24V supply and both controller ICs are damaged (which could further damage the motor). Recommend the purchase of a grinding pen, if available in your location.

[barrymerridan]

The dip switches are set different on both boards, surely they should be the same.

[chocomochino]

Professor! (That's how i refer about you to my wife) i was just waching this series, what happened to the Arcade game? they worked?? is there another video in these series? greetings from mexico

[Dutch_off_grid_homesteading]

Heya, that is a lot of work have to see P3

[felipehernandezhernandez]

La memoria eeprom nunca vi una dañada siempre capacitores y relays y dip swcth sucios por el polvo en algunas ocaciones el controlador del motor de C A, saludos desde mexico