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High Power variable voltage mod for C7042 APB

90941 Views 306 Replies 59 Participants Last post by  Gavin84
How would you like SH type power, the ability to adjust voltage all for next to nothing? Yes? Well read on!

You need
Craft knife
Soldering iron
solder sucker
2x R010 resistors

Difficulty level 2/10 easy enough for teenagers or adults.

Stage one, remove power connector, bend up a leg and refit.

Use solder sucker to remove solder.

Be careful there is a small track on the connector side. If it breaks just use a wire to link from the diode to the side leg.
Prise connector up when all solder has gone

bend up the end leg

Solder back onto board with remaing two legs and solder a thick wire to the bent up leg. Feed wire through 5 volt regulator hole as shown

Stage 2, cut track and solder wire to it
flip board over and with the craft knife cut through the large track shown, cut back and forth until it is cleanly cut. Check with a meter if you have one

Scrape off some of the green stuff and tin the track with some solder. Now solder the wire to the track

Stage 3, add two resistors to double the current trip point
Identify the two resistors R010 in the centre of this photo. Add extra solder either end as shown.

Now solder your new R010 resistors (size 2512) directly on top.

Use a standard C7024 power supply for the untouched connector (this powers the computer)
Use a 0-15V 20-30 Amp power supply for the modified connector (this goes to the power section)

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Thanks Riko this looks fantastic, reckon I need an appointment to the eye specialist to get new glasses so I can attempt this, or talk to my local electronics guys and offer them a slab of beers

Can't wait for you guys to figure out how to get RichG's laptower working with the APB if at all possible.

I reckon I'm now a convert from PB Pro SH to APB C7042, great work guys, brilliant, absolutley brilliant
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QUOTE (MrFlippant @ 29 Jun 2011, 13:23) <{POST_SNAPBACK}>This would be for people who really push those limits regularly.

Looking forward to pushing as hard as I can
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As an electronics clutz and with eyes and hands that are certainly not suitable for any fine soldering work it has taken me over 4 years to muster up the courage to take this mod on.

Not only did I attempt this mod but I also had to work out how to make a cord with the right plugs to connect the APB to my old variable 6v-16v, 25 amp PSU (another big worry I had).

It took me just over 4 hours to complete the whole task (mostly because I could not get past step 1 to de-solder the legs on the power connector) and RikoRocket's instructions are great and very easy to follow even for me.

Anyway the time & effort was worth it with the job being a success first go and I now am back to the serious PB Pro SH type power, (have to learn how to drive again).

One question I have is that after the mod my PSU will dial up to the full 16v (approx. 15.5 to track) but will now not dial down any lower than 12v, does this make sense to anyone.

The impact on the track is now a voltage range from 12v to 15.5v which is fine for our normal racing, however I had a few younger kids around on a race night last week and it would be nice to turn down the voltage to say 10v for the younger ones.

Thanks again Riko for this mod, whilst I doubted my ability to do it for a long time it was very easy to follow despite my extended time frame to complete.
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QUOTE (chris99 @ 31 Oct 2015, 23:53) <{POST_SNAPBACK}>Are you using the Scaley 15v power block in the APB computer power socket and the variable psu in the track power socket?


Thanks Chris & Ade for your repies,

I am using the Scaley 15v power block in the untouched APB power socket to drive the computer and my variable PSU in the modified socket to deliver power to the track.

It seems strange that the PSU won't go any lower than 12v when it is plugged into the APB and I can otherwise dial it back to as low as 6v.

That said I reckon I applied a fair bit of heat to the back of the power socket area of the board for a long time trying to desolder the legs (in the end I actually broke the back leg that you need to bend up, so I was pretty happy there was just enough left to solder the new wire too). Maybe I have scrambled something a little during that process.

Another question (just to prove my electronic clutziness if that is a word) is regarding cutting the track on the back of the board, in RikoRocket's photo it looks like only the green bit is cut away leaving the silver bit in place which is what I did, should I have cut through the silver bit to scrape it all away?
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Good call Mr Flippant, I unplugged the PSU from the modified socket and just left the Scaley brick in the unmodified socket and I could drive a car.

Now for the more work, any suggestions?
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Thanks everyone and thanks for that extra photo Chris.

I reckon my issue is I didn't cut all the way through the track (I thought I should have) so I will summon up the courage to go back in, finish the job and report back.

Can't do it tomorrow though as I am off to see Fleetwood Mac in Melbourne and feel like an Adolescent again (can't wait to see and hear Stevie Nicks one more time
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Thanks Greg for the extra close up photos.

I have now cut the track properly and have a successfully completed mod

I can't emphasise enough just how electronically useless I am, so if I can achieve this mod most of us should be able to (just allow plenty of time if you think you are at my "lack of skill" level).

My variable PSU now adjusts through the full range of 6v to 16v, although as low as I will need to go is 10v to avoid interfering with the lane changes etc.

Thanks again to everyone here for your help, it is always much appreciated.
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I agree Chris the biggest issue I had was the desoldering of the power socket, in the end the back leg breaking turned out to be a blessing as it released the socket (just lucky it broke with enough length to solder the wire onto).

Off Topic, Yes Fleetwood Mac were fantastic, they shouldn't be able to perform like they do at or near 70 years of age, they were not as good as they were in their prime but most of the audience weren't in their prime either, so it was a good balance.

Given the hard and fast life they have led they have done well to make it this far and still be able to perform.
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Good luck wplatt, let us know how you get on.
Good work wplatt, well done

It has to be an easy mod if I was able to complete it, albeit 4 hours longer than it took yourself
, it's certainly worth the effort though.
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Hi Riko,

I may be having a small issue following this mod.

On the APB there are 2 lights (red and green) and when I plug the leads (standard Scaley power supply and variable PSU) into the APB these turn on and stay on.

Every now and then (not too often) I have noticed the red light goes out and this seems to coincide with a lock up of SSDC, the fix is to restart the APB and restart free practice in SSDC.

Does this make any sense with changes I have made with the Mod?
Thanks Riko,

After your reply above I had a play this morning and the red button on APB & the red light in the bottom corner of SSDC screen are working as expected (I.e. both are not on when SSDC and APB are working together).

I suppose I only noticed the red light on the APB was off when I had to deal with SSDC locking up (which is not very often and usually after a track short), so I assumed it was a problem.

It's good to know how the red lights work together so I know when all is OK and understand when things are not.

Thanks again for your response, it's very much appreciated.
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