I've got about 10 or 15 VIC-20 but 4 of the are dead and produce a 'black screen of death'.
I have already done the known checks like e.g. fuse check, reset check, cartridge check, blind load comands, heat check on chips, etc., but to no luck
I have repaired tons of C64 and the C64 is known for a rather high PLA chip failure.
Now, which chip would you desolder and replace first ?
Jogi once told me every VIC-20 will produce a empty border screen if only the VIC is still in the board, but that would mean a lot of desoldering
Does the VIC die often ? Or do the rams fail more often ? Or the CPU ? (it doesn't fail often in the C64, btw.) The kernel is socketed on some of them, so this one can be ruled out on 3 of the 4, I think.
Thanx for any repair suggestions !
VIC-20 black screen - what do check/replace first ?
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Re: VIC-20 black screen - what do check/replace first ?
Yes it does and the main cause is exposure to high temperatures for extended periods of time. All it takes to prevent that is a small heat sink...Overdoc wrote:... Does the VIC die often ?
Be normal.
Either purifying water or making booze?Jeff-20 wrote:distillation?
For what it's worth, the video chip does tend to run hot and a heat sink may help. However there are many Vic-20s out there that have run for many years without a heatsink on their video chip.
I had one Vic-20 run for a couple of years on 7x24 basis running a "homebrew" house alarm system.
During MegaCart testing, I have had Vic-20 on for weeks at a time and have yet to have a 6560 fail on me.
Mega-Cart: the ultimate cartridge for your Commodore Vic-20
Yup, it's in the "Serious scientific applications" thread. It takes a week and a well optimized program (many tries to get the values right) to get to 94 %vol. The biggest cause of inaccuracy is that the voltage varies from 220 to 230 or something like that.
Many VICs got a broken AD converter when doing that, it's the long data cord which causes some peaks.. eslapion knows these things. It should be optically separated but it was never done.
Many VICs got a broken AD converter when doing that, it's the long data cord which causes some peaks.. eslapion knows these things. It should be optically separated but it was never done.