Thanks

Here is the article (note that the below article speaks directly to of the L01.1A chassis for a 29" model, not the L01.1U chassis for the 27" model):

Philips L01.1A chassis
I am beginning to see a few late-model 29PT2255/79R and 29PT2252/79R Philips TVs. I am talking about the L01.1A chassis, which came onto the market about 2001 onwards. The usual problem is that the set is dead due to the fact that the switchmode power supply is cactus.

The cause is not yet fully understood but this fault normally occurs during power surges. To fix it, I order and install what I call "Fred's Mod Kit", named after a friend of mine who repairs these sets under warranty. He found that eight parts usually need replacing - the chopper transistor (7521), its driver (7522), IC7520, R3523, R3530, D6523, D6524 and possibly D6525, which is not always fitted.

Of course, strictly speaking, this isn't a modification kit but only a replacement parts list. Perhaps a modification will come out in due course?

Another problem that is occurring is hum in some Philips models. One in particular comes to mind, the model 29PT4873/79R (L9.1A chassis), which can get particularly bad if placed on a resonating wooden table.

The cause is a deflection yoke with vibrating windings and the solution is to remove it and dunk it in Estapol varnish. Beforehand, it is a good idea to mask any areas that might be critical such as where it contacts the picture tube and the three rubber spacers.

The procedure should be repeated three times, allowing it to dry after each dunking before reassembling it onto the tube neck. That should stop the windings from vibrating and fix the problem once and for all.

http://ths.gardenweb.com/forums/load/electronics/msg0300341010556.html ?
http://ths.gardenweb.com/forums/load/electronics/msg0502124025007.html ?
http://ths.gardenweb.com/forums/load/electronics/msg0604415810551.html
http://www.freelists.org/archives/techassist/11-2005/msg00433.html
http://www.freelists.org/archives/techassist/11-2005/msg00435.html
http://www.freelists.org/archives/techassist/11-2005/msg00445.html

From
http://wa6ati.com/NAP-WEB.html

BRAND NAP
MODEL: MS3252S431
CHASSIS: ch L01-1U AC7638
Keyword: Shutdown
SYMPTOM: MS3252S431 ch L01-1U AC7638. horiz squeal at turn on, horiz freq off set shuts down. after sevral attempts to power up unit will come on and usually stay on.
CURE: Checking capacitors in the horizontal drive circiuit the tech found cap 2455 a 47mf25v in hdt circuit defefective. Replacing the device the symptom was cured.- Thanks to DD Mountain View, Ca.

Problem: Dead Set (chirping sound when plug to AC outlet)

Solution #1: replaced 7460 (BU4508DX horizontal transistor)
Result: power is up for 2-3 seconds then it shuts down automatically.

Solution #2: replaced 2455 (47uf/25v pol. electrolytic cap)
Result: YEHEY, i got a working 32" TV now.

COST of my 32" TV:
Dead TV = $0.00 (free)
BU4508DX = $14.00 (local electronic store)
47uf/25v cap = $0.99 (fry's electronic)
Total=$15.00

Note:
- use a replacement capacitor with the correct voltage
- i read from other post that BU4508DX is the same as BU2508DX which is the same as NTE2353 that you can buy from fyr's for $7.00
- I guess it's normal for these series of TV's to display raster after 3 seconds, any violent reaction??????