How to Debug a Newly Developed Circuit Board?

时间： 2023-12-23 来源：SIFU News

技术问答

选型帮助

研发客服

商务客服

For a newly designed circuit board, it is often difficult to debug it, especially when the board is relatively large and there are many components, it is often impossible to start. But if you master a reasonable set of debugging methods, debugging will be more effective.

For the new PCB board that has just been taken back, we must first observe whether there are problems on the board, such as whether there are obvious cracks, whether there are short circuits, open circuits, etc. If necessary, check whether the resistance between the power supply and the ground wire is large enough.

Then it’s time to install the components. Modules that are independent of each other, if you are not sure to ensure that they work normally, it is best not to install them all, but to install them part by part (for relatively small circuits, you can install them all at once), so that the fault range can be easily determined. When you encounter problems when you get it, there is no way to start.

Generally speaking, you can install the power supply part first, and then power on to check whether the output voltage of the power supply is normal. If you are not too sure about power up (even if you are sure, it is recommended that you add a fuse, just in case), consider using an adjustable regulated power supply with current limiting function. First preset the overcurrent protection current, then slowly increase the voltage value of the regulated power supply, and monitor the input current, input voltage and output voltage. If there are no problems such as overcurrent protection during the upward adjustment process, and the output voltage also reaches normal, then the power supply part is OK. On the contrary, it is necessary to disconnect the power supply, find the fault point, and repeat the above steps until the power supply is normal.

Next, install other modules gradually. After each module is installed, power on and test it. When powering on, follow the above steps to avoid overcurrent and burn out components due to design errors or/and installation errors.

There are several ways to find faults:

①Measurement Voltage Method

The first thing to confirm is whether the voltage of the power supply pins of each chip is normal, and then check whether the various reference voltages are normal, and whether the working voltage of each point is normal, etc. For example, when a general silicon triode is turned on, the BE junction voltage is around 0.7V, while the CE junction voltage is around 0.3V or less. If the BE junction voltage of a triode is greater than 0.7V (except for special triodes, such as Darlington tubes, etc.), it may be that the BE junction is open.

②Signal Injection Method

Add the signal source to the input terminal, and then measure the waveform of each point in turn to see if it is normal, so as to find the fault point. Sometimes we also use simpler methods, such as holding a tweezers by hand, to touch the input terminals of all levels to see if the output terminals respond, which is often used in audio, video and other amplification circuits (but pay attention to the This method cannot be used for circuits with high voltage or high voltage circuits, otherwise it may cause electric shock). If there is no response at the previous level, but there is a response at the next level, it means that the problem lies in the previous level and should be checked.

③ Of course, there are many other ways to find the fault point, such as looking, listening, smelling, touching, etc.

"Looking" is to see whether there is obvious mechanical damage to the components, such as cracking, blackening, deformation, etc.; "Listening" is to listen to whether the working sound is normal, such as some things that should not be ringing, the place where the sound should be heard No sound or abnormal sound, etc.; "smell" is to check whether there is any odor, such as the smell of burning, the smell of capacitor electrolyte, etc.

For an experienced electronic maintenance personnel, it is very sensitive to these odors; "touching" is to test whether the temperature of the device is normal, such as too hot or too cold. Some power devices will heat up when they work. If they feel cool to the touch, it can basically be judged that they are not working. But it doesn't work if the place that shouldn't be hot is hot or the place that should be hot is too hot.

General power transistors, voltage regulator chips, etc., work under 70 degrees is completely no problem. What kind of concept is 70 degrees? If you press your hand up and you can hold it for more than three seconds, it means that the temperature is probably below 70 degrees (be careful to touch it tentatively first, and don't burn your hand).

发送到邮箱 |
+1 赞 0
收藏
评论 0
| 转发至：

本文由上山打老虎转载自SIFU News，原文标题为:How to debug a newly developed circuit board?，本站所有转载文章系出于传递更多信息之目的，且明确注明来源，不希望被转载的媒体或个人可与我们联系，我们将立即进行删除处理。

全部评论（0）

暂无评论

高速PCB设计经验指南

设计高速系统并不单需要高速元件，更需要天才和仔细的设计方案。设备模拟方面的重要性与数字方面是一样的。在高速系统中，噪声问题是一个基本的考虑。高频会产生辐射进而产生干扰。边缘极值的速度可以产生振铃，反射以及串扰。如果不加抑制的话，这些噪声会严重损害系统的性能。本文介绍高速PCB设计经验指南。

设计经验发布时间 : 2024-03-01

常用的高频高速电路板材料DK和DF对比

高速产品更注重板材的介电损耗（Df）。市场上常用的高速材料的等级也是根据介电损耗（Df）的大小来划分的。不同的基板材料根据基板的介电损耗分为常规损耗、中损耗、低损耗、极低损耗、很低损耗。）五个传输信号损耗对应等级。

设计经验发布时间 : 2023-12-22

超全的pcb失效分析技术

PCB作为各种元器件的载体与电路信号传输的枢纽已经成为电子信息产品的重要而关键的部分，其质量的好坏与可靠性水平决定了整机设备的质量与可靠性。随着电子信息产品的小型化以及无铅无卤化的环保要求，PCB也向高密度高Tg以及环保的方向发展。但是由于成本以及技术的原因，PCB在生产和应用过程中出现了大量的失效问题，并因此引发了许多的质量纠纷。本文介绍pcb失效分析技术。

设计经验发布时间 : 2024-01-02

What Problems Can an Impedance Circuit Board Help With?

What problems can an impedance circuit board help with? SIFU will explore in this article.

技术探讨发布时间 : 2023-12-20

Four Points to Control the PCB Cost: PCB Layers, PCB Dimensions, Manufacturing Difficulty and PCB Sheet Material

In the PCB design, the factors that affect the cost mainly include the following four points: PCB layers, PCB dimensions, Manufacturing difficulty and PCB sheet material.

技术探讨发布时间 : 2023-12-19

How Do You Connect Wires to a Circuit Board Without Soldering?

In this article, Greenconn will delve into the fascinating realm of wire-to-board connectors and explore how they enable seamless wire connections to circuit boards.

技术探讨发布时间 : 2023-10-30

IS6630A/C/D with Three-way Output Enables DDR Power Supply Integration, Saving the Space on the PCB Board And the Required Devices

As a fully integrated DDR power supply integrated power supply solution, IS6630A / C / D is mainly used in high data transmission rate / wide output voltage range of pen, data center and other industries, taking into account high efficiency, high performance, while having a smaller application volume, can match the mainstream market demand, and actively enable the development of DDR industry.

应用方案发布时间 : 2023-10-02

赛孚电路一文告诉你们如何区分HDI PCB的阶数

在 PCB 领域，我们常常听到 4 层一阶 HDI、6 层二阶 HDI、8 层三阶 HDI 等表述，赛孚电路来教大家如何区分HDI PCB的阶数？

技术探讨发布时间 : 2024-09-14

深圳市赛孚（SIFU）电路科技有限公司成立于2011年，公司由多名电路板行业的专家级人士创建，是国内专业的PCB/FPC快件服务商之一。公司成立以来，一直专注样品，中小批量领域。快速的交付以及过硬的产品品质赢得了国内外客户的信任。公司是广东电路板行业协会会员企业，是深圳高新技术认证企业。

PCB 软硬结合板高多层PCB HDI PCB 高频高速PCB FPC PCBA

授权代理商 - 深圳市世强元件网络有限公司线上商城技术资料

展开

Ceramic Packaged All-solid-state Battery That Can be surface mounted to circuit board | Maxell

Maxell, Ltd. has developed a ceramic packaged small type all-solid-state battery that uses sulfide based solid electrolyte (hereinafter “Ceramic Packaged All-solid-state Battery”).

新产品发布时间 : 2021-04-17

PCB线路板如何助力新能源汽车创新？

PCB多层板作为电子元器件的重要支撑体，其技术已经相当成熟，广泛应用于通信、消费电子、计算机等多个领域。然而，在新能源汽车这一新兴领域，PCB多层板的应用却开辟了新的天地。新能源汽车的电动化、智能化、网联化趋势，对PCB多层板提出了更高的要求，同时也为其带来了前所未有的市场机遇。本文中赛孚来给大家介绍PCB线路板如何助力新能源汽车创新，希望对各位工程师有所帮助。

技术探讨发布时间 : 2024-08-28

METZ CONNECT Angled X-coded Circuit Board Family – Space Saving Applications

The angled X-coded circuit board family impresses with its diverse application possibilities. They are available in three versions that adapt wall thicknesses from 0-2.5 mm, up to 4 mm and 5 mm. The integration in sheet metal as well as die casting is possible without any problems.The entire family is THR solderable in order to meet the highest demands here as well. These connectors correspond to the DIN EN 61076-2-109 standard and can transmit data rates of up to 10 Gbit. This is achieved using length-compensated contacts.

应用方案发布时间 : 2020-12-15