Vic 20 startup time

[RiSXC]

Hi I just got a question

my Vic takes about 15 seconds to startup is this normal ? this seems a bit long to me

otherwise I cannot see anything wrong with it

and if this is not normal , any Ideas as to why it wil do that ?

[6502dude]

I have not seen a Vic-20 take 15 seconds to start.

However, I have seen variations in amount of time to start between machines.
I think the longest, that I have observed, may be in the order of a 2 or 3 seconds before screen display.

[Jeff-20]

Could you give us a boot log to examine?

When that happened to me, the video was giving out. The computer had started, but the video took about 15 seconds to catch up. It eventually failed all together. This doesn't seem to be what's happening to you. Your problem sounds unique.

[RiSXC]

uhhm bootlog ?

I am not familiar with that how do I get to the bootlog on the vic ?

if you tell me I gladly see what I can do

[Jeff-20]

Just a joke. Sorry. Welcome to our forum! We have a lot of great members. I'm sure someone here will help us solve this problem.

[Mike]

It could be a problem with the RC circuit(s) before the 555 that switches the reset line. Cold solder perhaps.

The start time also slightly depends on the memory configuration. More memory takes more time in the RAMTAS routine to test. But, as 6502dude pointed out, that time doesn't exceed ~3 seconds.

Michael

[RiSXC]

Here is some pics of it I think it is the early version.

first startup from cold 15 secs
second start 9 secs
I loaded a few games and it seems fine once it started.

[Mayhem]

Ah, a PAL 2 prong version, much like my own. Not seen those a lot. Given the Spectrum in shot, I'm assuming you must also be British

Completely OT here, but what's the C64 Handic cart in the background on the table?

[6502dude]

If you have a multimeter, check VCC and make sure it is 5.0 vdc +/- .1vdc

Then check if AC ripple on VCC line exceeds .1 vac

On spec, I would change the electrolytic filter capacitors in power supply.
These should be 4,700uf and 100uf units for Vic-20 with two prong 9VAC adapter.

Vic-20 is 20+ years old and the power supply electrolytic capacitors really should be replaced as part of preventative maintenance anyway, especially if unit has been in storage for extended period of time.

[RiSXC]

Well actually I am South African

the c64 handic cart is used with the VideoTextModem

here is a pic of it



seems to be a beltel program om the cart.

[RiSXC]

I think you onto something with regards to the caps
it might just be the devils!

hmm time to wield my soldering iron (cue dramatic music)

while I am at it I think I will add some heatsinks to the IC's

juuust in case..

[ral-clan]

I am not an electronics expert at all....I will defer to 6502dude....but my first reaction on reading your problem was that capacitors in the power supply might be slow to charge.

I have an old 1525 printer that can't drive the printhead until it's been on for a few minutes. I'm suspecting capacitor problems for that too.

So please let us know if a capacitor change helps things. Thanks.

[RiSXC]

ok I opened the case

here is what I found

The one 4700uf got a dent on the side
and the following has me worried!




that part does not look right to me!
any Idea what it is and how to test ?




here is a pic of the board

[6502dude]

I am not an electronics expert at all....I will defer to 6502dude....

I am certainly not an expert.

I have an old 1525 printer that can't drive the printhead until it's been on for a few minutes. I'm suspecting capacitor problems for that too.

Sounds like power supply capacitors may be your issue as well.
Here is simple chart of electrolytic capacitors failures:



If you have significant decrease in capacitance (which will occur over time), the power supply will not be able to supply sufficient current to drive the print head.

[6502dude]

Try changing these:



Most probable culprit is the big grey one (4,700uf)
Changing little blue one (100uf), is not a bad idea while you have soldering iron out.