2254C build/support thread

Little by little. Probably you measure "PCB power in" at wrong point.
Measure the voltage at PSU out
The voltage after diode rectifier should be in range 30....40V.

I can not open the 2254c Manual on Coppermine.
It's a Wordpad Doc and when I try to open it ,
it says I' don't have the Windows 97 graphics file converter.
I'm running Windows XP Pro.
Could someone convert this file and e-mail it to me. Help
[email protected]

someone should make a PDF 

i'll can do it but it won't be for a few days probably....

Igor said:

Little by little. Probably you measure "PCB power in" at wrong point.
Measure the voltage at PSU out
The voltage after diode rectifier should be in range 30....40V.

Click to expand...

Thanks Igor,
I measure the PSU out and got this Voltage!
so I got now 24 V psu IN and out 24 V
When I connect the wires to PCB BOARD I got 15V I changed th Lm317 too !

I'm till here !

Winetree said:

I can not open the 2254c Manual on Coppermine.
It's a Wordpad Doc and when I try to open it ,
it says I' don't have the Windows 97 graphics file converter.
I'm running Windows XP Pro.
Could someone convert this file and e-mail it to me. Help
[email protected]

Click to expand...

2254c_build_manual_by_Reanimator_.pdf
files.me.com/umitceyhan/9q7rij]files.me.com/umitceyhan/9q7rij]files.me.com/umitceyhan/9q7rij

33609J.pdf
files.me.com/umitceyhan/glxxq8]files.me.com/umitceyhan/glxxq8]files.me.com/umitceyhan/glxxq8

PSU and calibration.rtf
files.me.com/umitceyhan/lt1p7m]files.me.com/umitceyhan/lt1p7m]files.me.com/umitceyhan/lt1p7m

Bom page 1
files.me.com/umitceyhan/4iau1x]files.me.com/umitceyhan/4iau1x]files.me.com/umitceyhan/4iau1x

Bom Page 2
files.me.com/umitceyhan/ue6vat]files.me.com/umitceyhan/ue6vat]files.me.com/umitceyhan/ue6vat

Edit : you got them

cheers,

Thank you for for taking the time to list all the information.
Robert

Winetree said:

Thank you for for taking the time to list all the information.
Robert

Click to expand...

Cool

Thanks for the links!
Best,
Bruno2000

jandoste said:

Igor said:

Little by little. Probably you measure "PCB power in" at wrong point.
Measure the voltage at PSU out
The voltage after diode rectifier should be in range 30....40V.

Click to expand...

Thanks Igor,
I measure the PSU out and got this Voltage!
so I got now 24 V psu IN and out 24 V
When I connect the wires to PCB BOARD I got 15V I changed th Lm317 too !

Click to expand...

I'm till here  ???!

something on your main board might be drawing a LOT of current and pulling the 24v down to 15. this is not a good thing...

make sure all your electrolytic caps are around the right way. make sure there's no shorts anywhere. make extra sure that the 24v connection is wired correctly - if it's reversed it will probably do some damage and also might make the voltage drop..

is anything getting hot or smoking?

also try unplugging the output transformer - this will disable the output section - check if the power supply voltage still drops to 15v. if this fixes the voltage drop problem, you may have a short etc in the output section. make sure you haven't got a short under the T03 transistor (the big one) - there should be a spacer between it and the board, and the heatsink.

if nothing's getting too hot or smoking, you could try measuring the voltage drop across the power supply series resistors: R44, R43 etc and use ohms law to calculate the current draw.

kambo said:

hope you dont smoke  ;D

Click to expand...

Yes, I found my problem ! the problem was the 371 and changed it ! got right value on PSU !
But I got smoke here R"7 http://fr.mouser.com/ProductDetail/Vishay/FP001P47R0F6204B8/?qs=fCq1eTfc1mw5Npa1RfO%2f7g%3d%3d !
Why ? I don't know so baddddddd!

i told you to, check your components twice, before fire_up....

is it R7" next to the trimpot 47R....between 2n3055 transistor... then you are lucky

its not a big deal.... change ur resistor....
before u fire_up again:
set that trim_pot somewhere in half.... what ever the turn value, half it for now.... also, change that resistor with 1/2 w version...


EDIT : one more trick for you... when you power up, keep your finger on this resistor... if it starts to get really hot with in seconds, turn the unit off, and trim more CV... try again...  actually i have posted before  about where to keep that trimpot if you dont wanna burn ur 47r resistor... read well this back pages... u will be fine...

kambo said:

is it R7" next to the trimpot 47R....between 2n3055 transistor... then you are lucky

its not a big deal.... change ur resistor....
before u fire_up again:
set that trim_pot somewhere in half.... what ever the turn value, half it for now.... also, change that resistor with 1/2 w version...


EDIT : one more trick for you... when you power up, keep your finger on this resistor... if it starts to get really hot with in seconds, turn the unit off, and trim more CV... try again...  actually i have posted before  about where to keep that trimpot if you dont wanna burn ur 47r resistor... read well this back pages... u will be fine...

Click to expand...

Thanks Mr. Kambo
I "finished" the Unit !! lol lollllllllllllllllll
But it was so longggggggg with the PSU Anyway, what the next ?
I know it joky but I'll trunback Great project Igor ! 

well, if its passing audio, and everything seems to be working, then get on with the calibration  ;D
check early pages of this thread, lots of info available...

kambo said:

well, if its passing audio, and everything seems to be working, then get on with the calibration  ;D
check early pages of this thread, lots of info available...

Click to expand...

again me
well, I think I got a small problem with Gain makeup and threshold!
Gain is low and when I increase it I have no different  level !
and threshold is same !
Cheers

PS: Haima I have forgetten to say THANKS !

both the threshold and make-up gain are varied the same way (by a string of resistors to ground from the emitter of a transistor amp...) so if there's a connection problem to the front panel controls i'm guessing signal will still pass through the unit but you will be stuck at the "lowest gain" & "highest threshold" settings. so look for problems in the connection to the front panel board or on the front panel board/switches themselves.

if you unplug the make-up control does the level change?

does the hi-pass filter / attack and release controls work? i imagine it could be hard to tell with a threshold stuck at the top! perhaps none of the front panel controls work?

actually, as far as i can tell from the schematic the unit looks like it would pass signal without ANY front panel connections (?). so perhaps you have something fundamentally wrong with your front panel PCBs or connections to them.... and gain/threshold are the most obvious.

haima said:

both the threshold and make-up gain are varied the same way (by a string of resistors to ground from the emitter of a transistor amp...) so if there's a connection problem to the front panel controls i'm guessing signal will still pass through the unit but you will be stuck at the "lowest gain" & "highest threshold" settings. so look for problems in the connection to the front panel board or on the front panel board/switches themselves.

if you unplug the make-up control does the level change?

does the hi-pass filter / attack and release controls work? i imagine it could be hard to tell with a threshold stuck at the top! perhaps none of the front panel controls work?

actually, as far as i can tell from the schematic the unit looks like it would pass signal without ANY front panel connections (?). so perhaps you have something fundamentally wrong with your front panel PCBs or connections to them.... and gain/threshold are the most obvious.

Click to expand...

-if I unplug the make-up control the level is same.

-Hi-pass and attacks, reales controls are working. and the meters work too but I think I have to finish the calibration! may it's a calibration problem?

I'll check them I hope I'll fine it

Thanks,

good.

so i guess really inspect everything about the threshold and makeup switches, components, connectors and also the main pcb & components in the area related.

good luck! glad the rest of it seems to work.

haima said:

good.

so i guess really inspect everything about the threshold and makeup switches, components, connectors and also the main pcb & components in the area related.

good luck! glad the rest of it seems to work.

Click to expand...

I found some thing may it was that but I'm not sure ! on front panel controls I see R'17 is 00 ? 100 ohm?


EDIT : Yep, was 100 ohm I got the neve sound now

EDIT 2 : Thanks Kambo,Haima,Arnaud and Igor! Nice work Igor !!!!!

I realy don't like the case!





Uploaded with ImageShack.us