Canon 400D IR mod

[bojan]

Details on signal path. VB2ON is not where it should be.
Or not.. all depends on what kind of single gate it is, and if gate IC (ICPWR3) is healthy or not.
LPWRDET is Low power detector.. probably from Motorola.

[bojan]

The flex cable carrying VB2_ON and connections are OK, confirmed...

Then I cut the VB2_ON track, and shorted ICPWR3 pins 1 and 2.
Output (pin4, TIN) went HIGH... but TOUT remained LOW. And according to LV8013 data sheet, when EN and TIN are HIGH, TOUT should also be HIGH.

There is another strange thing with this LV8013... it has charge pump, output from it is ~13V, but motor is definitely powered from battery (via _-MOSFET that I had to replace earlier as faulty). At this moment, I am not sure where this voltage is used, and I can't imagine someone just blindly followed the data sheet and left all recommended components on bard, only to use only a fraction of the the functionality of the IC.

[glend (Glen)]

Bojan, I admire your persistence in debugging these problems as I don't have the skills or equipment to do it. Hope it works out for you. I would have bought a cheap donor camera by now and just swapped the board. I know through my 450D work that the cost of replacement boards from reputable sources is higher than just buying a beatup working camera body off ebay, and building a parts bin.

[bojan]

But I really enjoy all this debugging
Business-like approach was simply not encoded in my DNA, that's it.
And yes, I am watching ebay for a donor(s)..

[rcheshire (Rowland)]

There is another strange thing with this LV8013... it has charge pump, output from it is ~13V, but motor is definitely powered from battery (via _-MOSFET that I had to replace earlier as faulty). At this moment, I am not sure where this voltage is used, and I can't imagine someone just blindly followed the data sheet and left all recommended components on bard, only to use only a fraction of the the functionality of the IC.

Just a guess could the 13V be for the flash?

But I really enjoy all this debugging
Business-like approach was simply not encoded in my DNA, that's it.
And yes, I am watching ebay for a donor(s)..

This is great stuff and worthy of a book mark.

[xelasnave]

Do you have a good hammer?
Great thread.
Alex

[bojan]

Originally Posted by xelasnave

Do you have a good hammer?
Great thread.
Alex

Hammer is one thing I don't have... not for suggested application that is
My better half says I am a hoarder ...

[bojan]

Originally Posted by rcheshire

Just a guess could the 13V be for the flash?

After replacement of LV8013 (motor driver + power supply for lens) my Canon 400D is repaired, error99 is no more.
On the attached image (showing layout beneath the LV8013) it is obvious that +13V is used for lens power supply (one via leads to the bottom of the power board, which I didn't have to remove to solder in the new IC).

Couple of days ago I also received the UV-IR CUT filter (Rocolax 48mm, for my Canon 400mm 2.8L drop-in adapter), so it will be possible to do some real testing tonight if weather in Melbourne permits.

Pictures attached: two at the top row are taken with same lens, with "normal" (left) and modified camera (right).
The bottom image is taken with modified camera through Rocolax UV-IR-CUT filter.