superczar
Well-Known Member
- Joined
- Feb 5, 2008
- Messages
- 836
- Points
- 93
One of my old Paradigm Amplifiers had gone bust some time ago when someone in the house accidentally plugged the 110V device into a regular 220V socket
On Friday, my trusted old retina MacBook started artifacting/crashing the moment it would come under any kind of CPU strain making me realise that the motherboard is probably failing
Looked up a replacement machine on amazon only to realise that new MacBooks have been launched but availability is at least a month or two away.
Not willing to live with a windows laptop in the interim, I decided to tell the home ministry that I shall be ensconsed in my study evening onwards and all other worldly chores can take a hike for a day!
Pulled out my tool box and other associated paraphernalia and glad to report that both devices are back to the world of the living!
Paradigm Amplifier - PW Amp with Anthem Room correction
Dual board setup with the lower board containing the microprocessor/wifi/ Preamp and the upper board with SMPS and Power Amplifier
The power Amp was a TDA8954 with a symmetrical power requirement
The lower board had a separate power section on the SMPS
The zener diodes for the respective section were 2 X 22V and 5V respectively
The 5V bit was easy but getting a 22V symmetrical (+/-22V) wasn't- Looked up the data sheet for the TDA8954 which revealed a power requirement between +/-12.5-+/- 42V
Improvised a bit by hooking up two old Dell laptop supplies to yield a ghetto +19.5 V: 0 : -19.5V supply and a separate rail for the +5V microprocessor section
Lo- behold . the device sprang back to life and works as good as ever (probably better than before considering the beefier dual 5A supplies)
On the ghetto workbench being tested (kitchen sill)
Retina Macbook
A vast majority of failures on super-compact boards is because of microscopic fractures on the solder joints
Since it isn't practically possible to spot such soldering issues , the only viable solution is a solder reflow by using a controller temperature blast on a SMD reflow unit (which are super-expensive specialised equipment).
As a workaround , I have had good success with a makeshift reflow using a heat-gun and an IR thermometer in the past with a couple off errant boards but nothing this tiny ((For context, the size of the board below is the length of a wrigleys gum-stick)
Since I had nothing to lose, I decided to use the same ploy again by unplugging all the connectors and gently heating the board till the IR thermo read 225C.
After the board had cooled down, plugged everything back in again and , well, typing this out on the said retina MacBook!
All in all - and an upset home ministry aside - A saturday evening well spent
On Friday, my trusted old retina MacBook started artifacting/crashing the moment it would come under any kind of CPU strain making me realise that the motherboard is probably failing
Looked up a replacement machine on amazon only to realise that new MacBooks have been launched but availability is at least a month or two away.
Not willing to live with a windows laptop in the interim, I decided to tell the home ministry that I shall be ensconsed in my study evening onwards and all other worldly chores can take a hike for a day!
Pulled out my tool box and other associated paraphernalia and glad to report that both devices are back to the world of the living!
Paradigm Amplifier - PW Amp with Anthem Room correction
Dual board setup with the lower board containing the microprocessor/wifi/ Preamp and the upper board with SMPS and Power Amplifier
The power Amp was a TDA8954 with a symmetrical power requirement
The lower board had a separate power section on the SMPS
The zener diodes for the respective section were 2 X 22V and 5V respectively
The 5V bit was easy but getting a 22V symmetrical (+/-22V) wasn't- Looked up the data sheet for the TDA8954 which revealed a power requirement between +/-12.5-+/- 42V
Improvised a bit by hooking up two old Dell laptop supplies to yield a ghetto +19.5 V: 0 : -19.5V supply and a separate rail for the +5V microprocessor section
Lo- behold . the device sprang back to life and works as good as ever (probably better than before considering the beefier dual 5A supplies)
On the ghetto workbench being tested (kitchen sill)
Retina Macbook
A vast majority of failures on super-compact boards is because of microscopic fractures on the solder joints
Since it isn't practically possible to spot such soldering issues , the only viable solution is a solder reflow by using a controller temperature blast on a SMD reflow unit (which are super-expensive specialised equipment).
As a workaround , I have had good success with a makeshift reflow using a heat-gun and an IR thermometer in the past with a couple off errant boards but nothing this tiny ((For context, the size of the board below is the length of a wrigleys gum-stick)
Since I had nothing to lose, I decided to use the same ploy again by unplugging all the connectors and gently heating the board till the IR thermo read 225C.
After the board had cooled down, plugged everything back in again and , well, typing this out on the said retina MacBook!
All in all - and an upset home ministry aside - A saturday evening well spent
