The component density on this board is astonishing! The black-to-green ratio is roughly 1-to-1.

@retrogamesparty

4 жыл бұрын

All full of really sucky and really cheaply made custom chips and a substrate that loves to disintegrate as soon as you put a soldering iron near it.

@richardhead8264

4 жыл бұрын

@@retrogamesparty Thank you for adding more context and color to this undertaking!

Your videos are like a good detective novel !

Lisa: "Há, Há, Made you look 😛!".

Just found your channel and immediately subbed !!, great repairs mate, and love the in-depth analysis

Makes total sense to you and is a logical process. The rest of us have not a clue😂😂😂😂😂

Thanks! I have a board doing the exact same thing with colors, I know now a couple of things to look for thanks to your video

Love it... Great fix

Nice fix! I've used similar tricks on controller inputs (adding a strong pullup to override an internal short), but never on full-speed logic like that. Impressive that it works!

@retrogamesparty

7 жыл бұрын

I had to try a few different values of resistors to get it to work, i'm not an electronics expert by any means, transistors still confuse me sometimes so i'm never sure whether you want a higher or lower value resistor to affect the pull-up/down, I started with a 1.5k I think.

Great to see you fix another one :-)

@retrogamesparty

7 жыл бұрын

Thanks :) wasn't an easy one, I normally don't take these ones on because of the custom chips.

Nice Work

very clever - impressed

this was amazing man I really respect your skill set wish I had it!

@retrogamesparty

4 жыл бұрын

Taken me a long time to get this far and I haven't really done much repair in the last year.

Cool video,

Great save for that custom chip there =D Nice!

@GadgetUK164

7 жыл бұрын

BTW - I might consider swapping out the 157 at the same time, is there no chance the 157 was pulling it high?

@retrogamesparty

7 жыл бұрын

I thought that at first, my deduction was that I snipped the input leg on the 157 and it remained high, comparing it with other pins coming from the same custom which were properly cycling low I figured the custom wasn't driving low enough on that pin so pulled the input to ground via a resistor to get enough level for the 157 to do its job. The tracks are flaky as hell on those boards so I didn't want to desolder another chip if I didn't have to.

@GadgetUK164

7 жыл бұрын

+Retro Games Party Great!!! All bases covered then! =D

@retrogamesparty

7 жыл бұрын

I don't think the 157's have internal pull-up/down resistors because of the universal application of them, in hindsight I should have snipped one of the known working legs and compared that for absolute certainty but the board is back with its owner and they are happy.

@treadmillrepair754

7 жыл бұрын

Hi I am wondering looking fixing old arcade boards, this is a full time job or is a hobby for you? I am in electronics for 40 years, most of repair shops are closed here in my country . I fix treadmill machines for many years and still have a lot of job. Cheers.

THAT'S AMAZING!

nice one bud :)

hola. cuales son las memorias que debe cambiar para cambiar el juego de 4 player a 2 player . decime sus posiciones y cuantas son .gracias

repair from jan? fook me james you are behind. great job as always :)

@retrogamesparty

7 жыл бұрын

Yeah, my bad, i've some from last year and the year before to release still. Just making time to edit them.

ditto with j jones !!

Which chip controls the down on a konami tmnt ,i tried using the schematic in the manual but the pcb board isnt listed with a4 etc like in the book🙏🏻🤷‍♂️

Nice job. Pull-down resistor... I understand what is happening and what you have done (I formally studied electronics at TAFE for two years AND I have a large kinetic vocabulary) - but I would have put the board in the too hard bin like most guys. I love bootlegs as they ar e far easier to repair due to the lack of custom chip paranoia presence. Keep the videos coming. ☆♡☆ Ya... 5☆ Work hard to eat nice food, drive nice cars and kiss 'N cuddle pretty girls. Bye!!!

Hey, I have simpsons PCb which also shows "80" as BAD in the test menu, what did you do to fix that??

So why does my simpsons board when I start up it doesn’t play the sound during the intro but during gameplay sound works fine.

Aaaaaaaaaaaaa, the crt whine!

Hello. I'm hoping you see this as I see it's been a while since you've uploaded anything. I have a Simpsons Machine as well and I am getting these errors on the screen from 0:58. 16C BAD 891B 17C BAD 87D5 I have also noticed the 4 letters after BAD will change too. I know nothing about these machines and recently turned it back on after several years of it not being used. If you have any idea how to help me with this that would be very much appreciated. Thank you for your time

Do you have a website??

Forgive the stupid question from someone who isn't smart enough to understand this but why add the resistor? wouldn't it be better to replace the chip and that way it's not going to fail the same way in the future?

Looks like the chip is damaged and cannot pull that pin down. The pull down fixes it as it allows the signal to go low in the absence of being driven high. Neat fix.

@retrogamesparty

4 жыл бұрын

Was definitely a bit of a hail-mary play that one - a hunch that paid off and the first time to be fair that i'd introduced a passive into a circuit.

that's brilliant. Hardware hack :D

@retrogamesparty

7 жыл бұрын

Yeah, i've had to do that on a few boards either pull-up or pull-down, its the same principle as how input controls from regular switches work - there's +5 going to the switch and you ground it, but you'd get a spark and short circuit without the resistor in the path taking the current so you'd see a HI signal at the input pin then when you close the switch it will go LOW. The device accepting input usually inverts the signal so that you see a 1 in the relevant data address for that device rather than a 0.

nice monitor

@retrogamesparty

4 жыл бұрын

Thank you.

@paulmichaelfreedman8334

4 жыл бұрын

Original 1084 Amiga Monitor. I had one. Had afterglow in the phosphor, gave it a silky smooth picture.

I can only see ICs

RETRO GAMES PARTY, ^^)) 1.) Whats the difference between a PROM chip compared to a BI-POLAR PROM chip? 2.) Why does the HP comparator give false positive result and doesn't work correctly when comparator H&V counter chips? it loads the output pins or something because the HP comparator will say the counter chips are bad but aren't bad any reasons why?

@retrogamesparty

4 жыл бұрын

1) In the context i'm talking about they're the same thing. 2) No idea at all - I almost never use mine anymore, just use the scope to debug boards. The two common fails on the H&V counters are either floating / tied low-or-hi OR that they are not counting at the correct rate.