CDM Building questions

Kip · « **on:** 20 Jan 2005, 05:49 pm »

Quick question. I am getting +10.08 volts out of the +9 volt power supply. I don't know if there is a tolerance and if the +10.08 is within tolerance. Someone please advise. I have not pluged in the CD-PRO2M yet.

doug s. · « **Reply #1 on:** 20 Jan 2005, 05:53 pm »

Quote from: Kip

Quick question. I am getting +10.08 volts out of the +9 volt power supply. I don't know if there is a tolerance and if the +10.08 is within tolerance. Someone please advise. I have not pluged in the CD-PRO2M yet.

not sure this will be a problem for you - its 10.08v output reading will likely drop a bit when there's a load on it. likely, it would work at 10v anyway, even if the load dint cause the output to drop...

doug s.

SteveSun · « **Reply #2 on:** 20 Jan 2005, 05:57 pm »

there is a problem with the power supply... make sure all resistors are installed properly.

Kip · « **Reply #3 on:** 20 Jan 2005, 07:02 pm »

Hi Steve, Thanks for the help.

U1 A=15.9 O=17.12 I=29.5
U2 A=11.3 O=12.54 I=17.12

SteveSun · « **Reply #4 on:** 20 Jan 2005, 07:19 pm »

So, your first 2 stages of the regulator are all working fine. Please measure the folloing volage again: pin 3 and pin 2 of the op amp; voltage at pins R10 and R11. This will help me to pin-point the problem. Pay special attention to R10 and R11: R10 = 200, R11 = 249. Thanks.

Kip · « **Reply #5 on:** 20 Jan 2005, 07:44 pm »

Steve,

Op Amp Pin 2=5.6v Pin 3=6.3v
R10=10.1v R11=5.6v
The resistors were measured from the solder connection at the outside edge of the board not closest to the output connector. I double checked the printed values on the resistors and R10 is 200, R11 is 249.
Thanks again for the help.

SteveSun · « **Reply #6 on:** 20 Jan 2005, 07:54 pm »

So, the problem is the OP Amp pin-3 voltage: 6.3V is too high! It supposes to be only 5V. 5 x 449/249 = 9.01V, and now you will get: 6.3 x 449/249 = 11.4V. I will ask Ken to send you another LM336-5.0V, and that should solve your problem.

ken_diyzone.net · « **Reply #7 on:** 20 Jan 2005, 07:58 pm »

Hi Kip,

I'll send this out with the other missing part tomorrow.

Thanks
Ken

Kip · « **Reply #8 on:** 20 Jan 2005, 08:06 pm »

Thank you Steve! Should I do a test and swap the Op Amp with the +5 regulator and see if the +9 is correct?
I have one other question. I noticed that the electronic power switch LED's flicker on when main power is applied. I checked to see if there is voltage at the output pins. My meter does not have a hold function, but I do see voltage for a split second before the relays are activated. If the CD-PRO is to have the +5v first then what is the initial power up doing to the CD-PRO before the relays kick in? Is the power up sequence useless if main power is used every time, or is this 200ms power up and down (I am guessing here) to quick for any effect on the CD-PRO?

SteveSun · « **Reply #9 on:** 20 Jan 2005, 08:10 pm »

Hi Kip: that will help. Thanks.

Kip · « **Reply #10 on:** 20 Jan 2005, 08:44 pm »

I swaped OP Amps and +9 is still at 10.12v. +5 is at 5v. I checked the Op Amp on +9 (after the swap) and the new OP Amp is also 6.3v on Pin 3. I then checked the OP Amp that we thought was bad (now in the +5 board) and Pin 3 is 5v not the 6.3 it was on the +9 board.

SteveSun · « **Reply #11 on:** 20 Jan 2005, 08:56 pm »

Hi Kip: the Op Amp itself is fine. The problem is the voltage reference LM336-5.0V. This transistor should provide 5.0V voltage reference for pin-3 of the Op Amp. The LM336-5.0V on your 5V board is corrent: it provides 5.0V reference voltage for OpAmp pin-3. On your 9V board, you measured 6.3V on pin-3 of the Op Amp means LM-336 does does not provide correct reference voltage and this confuses the OpAmp. Please wait for the new LM336.

Regarding your other questions about initial power surge: I do not know the answer, and I will forward this question to Limin. There are about 1500 CD-Pro2 Kits running all over the world now, and so far, no one has even encounter any problems about the initial surge.

Kip · « **Reply #12 on:** 20 Jan 2005, 08:59 pm »

Thank you Steve. I thought the OP Amp was bad not LM336. I know enough to put it together, but not enough to debug and repair. What LM336 is bad? U1 or U2.

SteveSun · « **Reply #13 on:** 20 Jan 2005, 09:10 pm »

Hi Kip: LM336-5V is U4, that "black thing". OpAmp will amplify the diffference of the reference voltage and a sample of output voltage, and this amplified signal is used to control Q1 for voltage regulation.

Kip · « **Reply #14 on:** 21 Jan 2005, 12:13 am »

I just looked closely at U3 and U4. They are swapped on the +9 board and correct on the +5 board. Boy I assumed again. They looked the same and I assumed they were. Had a 50/50 chance on each board. The +5 board won.

ken_diyzone.net · « **Reply #15 on:** 21 Jan 2005, 02:48 pm »

Hi Kip,

So is it working properly now? I am just about to mail them out to you, but if they are ok, then I'll keep these (I pulled them out of another kit).

BTW, I am still sending the diodes.

Please let me know.

Thanks
Ken

Kip · « **Reply #16 on:** 21 Jan 2005, 04:56 pm »

Thank you Ken,

All is good the +9 is at +8.95v now. I only need the diodes for the sensor board. Now I can install the CD-PRO.

Kip · « **Reply #17 on:** 21 Jan 2005, 05:48 pm »

CD-PRO is in and I get the OPEN on the display. When I get the diodes and install the cd sensor all should be good. Thank you all for the help!

Kip · « **Reply #18 on:** 22 Jan 2005, 05:15 pm »

Sorry, but I need help again. Ken sent me the diodes for the cd detecting pcb. I installed the diodes, installed the pcb in the player and still get the open signal on the display. I inspected the pcb and confirmed that Q5 and the Molex connector are installed as per the manual. I put a volt meter on the detection pcb connector on the display board and get 5v on two pins.

SteveSun · « **Reply #19 on:** 22 Jan 2005, 06:58 pm »

Hi Kip: those 2 diodes are directional! You need to put the side with "black band" with the line on the PCB, not the triangle side. Can you check?