Virus B bought new 20 years ago - advice on repair
 

Hi

My name is Tim and I bought a Virus B around 20 years ago.
I have used it a lot up until 8 years ago when my son was born and it was not turned on for that period of time.

As i now have a bit more spare time on my hands i decided to get it out and plug it in. Only to discover that when i did power it up both LFO light stay on and the display flickers..

I though might be a dodgy power supply, so bought a new one off access virus official shop . Any how, i got the same issue with the new supply and therefore ruled that out as the problem..

Next I replaced the battery on the motherboard with a new one, still the same issue.

I found an article that suggested it could be the brown capacitor on the motherboard that needs replacing as they had the same symptoms and this seemed to resolve it for them.

however, not being an expert solderer, im a bit stumped on how to de-solder the existing one - do i have to do it from underneath on the bottom of the board..

I attach a pic of the inside of my unit

Any help much appreciated

Regards

Tim

Hi tim

Maybe try a factory reset. Hold both Lfo shape buttons down while powering on.

Worked for me. Worth a try :)

hi

if factory reset not solve i advice for replace the 2 capacitors ..for desolder these 2 caps you can to use desolder sucker (check image below ) or desolder wick .. if you are new in soldering i advice carefully.. this for not damage the print on motherboard anyway check you tube for a million of guide for soldering practical.
- Internal battery is for to preserve storage presets
- Power supply can to be tested with multimeter with the probes in output on connector that goes in female input of m.board , with measurements 12v ..
- capacitors can to be tested (after unsoldering them from the board) with capacimeters .

ps

you don't need to spend too much on the original power supply, but you can easily fit a laptop power supply (12v 2/3A )

https://www.dropbox.com/s/y6e4soemw1...ucker.JPG?dl=0

https://www.dropbox.com/s/deyszg3dh4...0wick.JPG?dl=0

Good luck

Orlando

Yes, you have to de-solder the capacitors from the underside. Remove the main circuit board if possible to gain access to the underside.

Use a low-wattage (15W) soldering iron with a fine (thin) tip to minimise heat/melting damage to surrounding electronics and components.

As orx65 suggests, heat the solder from the underside, use a solder sucker (as orx65 showed) to remove any excess solder while still fluid, and pull the capacitor out from the other side.

http://www.infekted.org/virus/images...b-bad-caps.png

^ Above pic shows the usual problematic capacitors on Virus B (shown within the dashed green box).

Thankfully the caps are not surface mounted.

I have further disassembly photos for a Virus Indigo, which is basically a Virus B with a keyboard and mod-wheels bolted onto it, which may show common detail regards the mainboard: Virus Surgery: Re-potting masterclass .... I know it was being disassembled for a different purpose (repotting), though, so is just a rough guide as to what you may find.

The Virus is relatively modular to disassemble, there are three boards - the mainboard with all the circuitry (with all the jacks running along the top), a larger board which all the knobs attach to on the opposing side, and a third smaller board for the LCD. You only need the mainboard. You may need to remove a ribbon cable or two. Detach the boards from each other and you should have full unimpeded access to both sides of the mainboard. Be careful with the power on/off switch as, if it's like my Indigo, it may be attached to the metal casing and the wires are short and won't travel far.

Thanks for taking the time to reply and help me out with advice
I think im a bit out of my depth here, not an electronics guy - but im willing to give it my best shot to try and get my virus back up and running..

I'll let you know how i get on !

Regards
Tim

Hi Tim,
Did you managed to fix your Virus B?
Cheers - Matt.