Trials & Tribulations of Chip Repairs & Upgrades

Here is another method of refurbishing Scalextric chip wiring. This time it is an older C7006 Rev E, often found in the original digital
cars from Scalextric. The wires used for the motor side were very stiff and often broke when they got older. I have also used this
method on newer, but sadly now defunct Rev G C7006s. Apart from refreshing the wires, you can also reduce the depth of the chip
but removing the white JST plug.



As you can see a slightly different layout to the Rev G version. So first thing was to remove the four main wires ...



The new wires laid out together with some header plugs such as you might use on an Arduino to provide a header plug. The pins
were pulled out of the holder and each one was soldered to an individual wire ...




With the pin firmly clamped in the old vice, it was a simple task to tin the wire and the pin then join them together with some solder.
Some
heatshrink was applied to cover and insulate the joint ...



Before each wire was soldered onto the board each pin was gripped with some pliers and bent through roughly 900. To make
the board even thinner, the large capacitor could be removed from the board and attached to a fly-lead ...

A couple of DPR chips arrived for some attention. These are a bit more fiddly to fix because the very top of supporting pins have
to be carefully removed to leave something to reattach the chip after fixing them ....... and you can't get any replacements.



This one has a blown NO2 MOSFET ...

This did not show any sign of physical damage but testing the MOSFETs revealed that PO3 had blown ...

In repairing these chips, both sets of the NO2 & PO3 MOSFETS were replaced with uprated ones to avoid one being weaker than the
other thereby causing further problems down the road.

Another C7006 lives to race some more days ..........



A badly burnt out NO2 mosfet with lot of black residue coating many of the components in the immediate vicinity. These required
careful inspection and measurement to ensure that they were still functioning.



Surprisingly, every thing survived and just need a bit of a spring-clean to improve their appearance. The yellow arrows show were the
copper tracks disintegrated on the PCB and were I added some surface mounted wire to reconnect things to get the chip running again.
The replacement NO2 is slightly skewed to ensure that at least 2 of the 3 mount points anchored it in place ......

And now for something completely different ...... an oscillator crystal ....



It's the white & gold thing next to the IX marking ...... it usually has a silver coloured cover.

This C7006 was fully uprated and re-flashed to InCar-Pro plus lighting added. Everything was tested and everything was working
before I put the new car back in it's display case ready to hand it over to it'd proud owner. Imagine my horror when the car was
eagerly placed on the track and ............ nothing ...

The problem had to be something to do with inserting and twisting the T-Piece that held the car in place. Upon opening up the car
the problem was obvious. The T-Piece had broken the crystal oscillator from the PCB. Searching through my dead-chip box I found
a suitable donor and replaced it; thankfully everything burst into life upon re-testing ...... phew.

QUOTE (GregK @ 25 Sep 2015, 21:59) <{POST_SNAPBACK}>Another C7006 lives to race some more days ..........



A badly burnt out NO2 mosfet with lot of black residue coating many of the components in the immediate vicinity. These required
careful inspection and measurement to ensure that they were still functioning.



Surprisingly, every thing survived and just need a bit of a spring-clean to improve their appearance. The yellow arrows show were the
copper tracks disintegrated on the PCB and were I added some surface mounted wire to reconnect things to get the chip running again.
The replacement NO2 is slightly skewed to ensure that at least 2 of the 3 mount points anchored it in place ......

Hi Greg, It has been a revalation for me reading and rereading this your thread. I have one C7006 Rev E incar chip with I believe, a burnt out NO2 MOSFET and I would like to try my hand and eye at repairing the chip. Twelve hours ago before reading (all day) your threads and posts I had not a clue regarding the magic of the digital in car chip. I would not know a MOSFET from a muppet till now. So my question is what soldering iron do I need to buy to replace the NO2. My digital soldering station and my smallest soldering (25w) iron are far too big for this type of work. I would guess that I must buy an iron perhaps less than 25w with a set of tips no more than 1.5mm dia with pointed tips Can you also advise where I can buy the NO2 MOSFETs I already have several 100 to 200 magnification jewelers head sets which I have to use for all work on my cars now such as installing a digital chip or even replacing a pu braid so I am under no illusion that repairing this chip will be a serious challenge. I never planned to grow old and decreped but it just seems to have crept up on me while I wasent looking. I read the new posts on this forum first thing each morning especially stuff like you and Riko and others in the team post and its an inspiration to me. I think you guys are absolute wizzards. Many thanks. We are never too old to learn.

QUOTE (GregK @ 12 Mar 2016, 01:50) <{POST_SNAPBACK}>Thanks Bryan for your kind words. As Sir Isaac Newton famously said ....... "I am standing on the shoulders of Giants" ..... and those giants are RichG & Rikorocket.

Can you post a picture of the damage on your chip? Then if you PM me your address I can then send you the relevant bits .......

Hi Greg, Thanks for that. Too kind. You have now decided me on something I have been afraid of for a couple of years IE:- "post a picture" on the forum. Someone once said to me "If we gave you enough number 8 fencing wire we reckon you could build a Boeing 747". Well it would be streaching things a bit, though I could use it to build a flying mechine. However "post a picture on the forum" So decision made I will try to use the method "PHOTO BUCKET which I once found instructions for on this forum. But more important I will go really really mad and pay a subscription to become a full ?? member on the forum (I owe you fellows at least that for all the enjoyment I have had over past times following the posts on here. I am led to believe that I could then post photos on the forum reasonably easily. You must however be made aware that I am not a techno, I have for example never owned or even ever used a mobile phone in my life. No techno but still a good old micro mechanical engineer. Bryan B.