Delta TDPS-150 Switching Power Supply

[Mike_2012]

Hello team,

I am recently working on repairs for Delta TDPS-150 switching power supply.
(I do not currently have its schematic available but working to reverse engineer it and hopefully
will soon post some information.)

Input 100 - 240V AC
Output 12V 12.5A max

I have included some PCB photos for your reference.
Anybody who is willing to share anything about this or ask questions is welcome


******************
Next - here's (1st Draft) rev-engineered schematic of the 'High voltage' side of the power supply.
All repairs so far had burned parts only on that side - never on the Low, 12V side.
So I have decided to skip the "12V" part of the schematic - at least until I get a
board where it appears damaged, otherwise this would not make sense to me to reverse-engineer.

High and Low voltage sides are galvanically separated by 2 transformers (L8, L9 are primary
windings of the 1st (Main) power transformer; L1 and L2 are the primary windings of the 2nd transformer) and 3 opto couples (U1, U2 and U9).
L3 transformer has both primary and secondary windings on high voltage side only.

Lower part of the schematic was the most complex part (to reverse-engineer (:-)) and likely
has a lot of errors - e.g.
most of the junction transistors have mismatched Collector, Emitter and Base. Several components
are not identified correctly - i.e. I have mistakenly drawn a transistor while it could be some
other component - like voltage detector, etc. (This is because of the cryptic 2-3 letter/number
on the SMD chassis making it difficult to determine correctly - with 100% certainty.)

(I have used Digi-Key's free "Scheme-it" to draw the schematic and unfortunately only when reaching
too far into this drawing found there was no easy way to make any changes - once the components got connected ...)

For approximately my initial ~10 repairs this is the list of most often failed components:
IC3845 (usually always with R98 1kOhm SMD resistor melted)
IC6562
Q12 (MOSFET)
Q801 (MOSFET)
R84 (0.33 Ohm/ 1W)
R907 82Ohm 1W through-hole
S1 and S2 fuses (4 Amp)


Notes:
U8 (IC3845) and U5 (IC6562) pins are not represented correctly - as shown on the diagram; I have only followed the usual "bottom-left" starting pin#1 convention as for the most (digital) chip
pin-numbering.
LM393 is correctly shown (except its PWR and GND (2 unnumbered pins) are not connected on the schematic); however I guess this is not critical for the analysis ?

Some diodes could be Zener diodes (or vice-versa) because I have relied on the PCB component markings
but can have errors.

All 'American' type resistors represents '0-Ohm' (bridge/protection) resistors on the PCB board and can be ignored while 'reading' of the schematic function.