Saltar al contenido principal

Repara tus cosas

Derecho a reparar

Partes y herramientas

Lanzado en Septiembre 16, 2016. Modelos 1660, 1778. Disponible en GSM o CDMA / 32, 128, o 256 GB / Oro Rosa, Oro, Plata, Negro Mate y Negro Brillante.

Preguntas 1638 Ver todo

vdd main short but no heat

so i have an iphone 7 in this morning and as title says i have a vdd main short, wire soldered on and drawing 2 amps but no sign of heat. can i raise the amps and if so what is the max

Contestado! View the answer Yo también tengo este problema

Es esta una buena pregunta?

Puntuación 0
Agregar un comentario

Kit de Destornilladores Manta

112 bits for every fix.

Upgrade Your Toolbox

Kit de Destornilladores Manta

Upgrade Your Toolbox

1 Respuesta

Solución Elegida

Hey Daniel. Looking for a heat signature can be tricky, especially when using a DCPS as the power source. Most bench power supplies offer current limiting protection. That means that when the current reaches the maximum set output, the PS will drop the voltage output in order to maintain the max current.

So when looking for heat, you are essentially hoping some component will give off this heat as a result of power dissipation. However, P=V*I (POWER equals VOLTAGE times CURRENT) through the component. So if your current is 2A but the voltage is essentially Zero (due to current limiting), then the power will be 0W...so no heat!

So the thing to do is either increase the current setting on the DCPS so that there is some voltage drop across the shorted component or use a battery which will not be current limited. The advantage of the DCPS is that you can bring it up slowly to avoid any catastrophic damage by a sudden surge of power.

The other thing to try is to start with a lower voltage, say 2V with a max current setting and then slowly build up the voltage. This can weed out the bad component before fully activating the logic board.

Fue útil esta respuesta?

Puntuación 5

Comentarios:

cheers @refectio , think i have burnt the short as when i connect the power lead to dc i wasnt gettin draw now its going upto 0.76 amps. when plugging dc in before pressing the button im getting around 0.16 amps before pressing power. need a new lcd to see if i have image now

- de

@refectio any idea why im getting 0.16amp draw before pressing power

- de

It could be just battery charging...

- de

Agregar un comentario

Añadir tu respuesta

daniel estará eternamente agradecido.
Ver Estadísticas:

Ultimas 24 horas: 0

Ultimos 7 días: 2

Ultimos 30 días: 16

Todo El Tiempo: 504